Scratch space for learning atproto app development
cduck.me
1import { Agent } from '@atproto/api'
2import { TID } from '@atproto/common'
3import { OAuthResolverError } from '@atproto/oauth-client-node'
4import express, { Request, Response } from 'express'
5import { getIronSession } from 'iron-session'
6import assert from 'node:assert'
7import type {
8 IncomingMessage,
9 RequestListener,
10 ServerResponse,
11} from 'node:http'
12import path from 'node:path'
13
14import type { AppContext } from '#/context'
15import * as Profile from '#/lexicon/types/app/bsky/actor/profile'
16import * as Status from '#/lexicon/types/xyz/statusphere/status'
17import { env } from '#/env'
18import { handler } from '#/lib/http'
19import { page } from '#/lib/view'
20import { home, STATUS_OPTIONS } from '#/pages/home'
21import { login } from '#/pages/login'
22import { ifString } from './lib/util'
23
24type Session = { did?: string }
25
26// Helper function to get the Atproto Agent for the active session
27async function getSessionAgent(
28 req: IncomingMessage,
29 res: ServerResponse,
30 ctx: AppContext,
31) {
32 const session = await getIronSession<Session>(req, res, {
33 cookieName: 'sid',
34 password: env.COOKIE_SECRET,
35 })
36 if (!session.did) return null
37 try {
38 // force rotating the credentials if the request has a no-cache header
39 const refresh = req.headers['cache-control']?.includes('no-cache') || 'auto'
40
41 const oauthSession = await ctx.oauthClient.restore(session.did, refresh)
42 return oauthSession ? new Agent(oauthSession) : null
43 } catch (err) {
44 ctx.logger.warn({ err }, 'oauth restore failed')
45 await session.destroy()
46 return null
47 }
48}
49
50export function createRouter(ctx: AppContext): RequestListener {
51 const router = express()
52
53 // Static assets
54 router.use('/public', express.static(path.join(__dirname, 'pages', 'public')))
55
56 // OAuth metadata
57 router.get(
58 '/oauth-client-metadata.json',
59 handler((req: Request, res: Response) => {
60 res.json(ctx.oauthClient.clientMetadata)
61 }),
62 )
63
64 // Public keys
65 router.get(
66 '/.well-known/jwks.json',
67 handler((req: Request, res: Response) => {
68 res.json(ctx.oauthClient.jwks)
69 }),
70 )
71
72 // OAuth callback to complete session creation
73 router.get(
74 '/oauth/callback',
75 handler(async (req: Request, res: Response) => {
76 const params = new URLSearchParams(req.originalUrl.split('?')[1])
77 try {
78 // Load the session cookie
79 const session = await getIronSession<Session>(req, res, {
80 cookieName: 'sid',
81 password: env.COOKIE_SECRET,
82 })
83
84 // If the user is already signed in, destroy the old credentials
85 if (session.did) {
86 try {
87 const oauthSession = await ctx.oauthClient.restore(session.did)
88 if (oauthSession) oauthSession.signOut()
89 } catch (err) {
90 ctx.logger.warn({ err }, 'oauth restore failed')
91 }
92 }
93
94 // Complete the OAuth flow
95 const oauth = await ctx.oauthClient.callback(params)
96
97 // Update the session cookie
98 session.did = oauth.session.did
99 await session.save()
100 } catch (err) {
101 ctx.logger.error({ err }, 'oauth callback failed')
102 return res.redirect('/?error')
103 }
104 return res.redirect('/')
105 }),
106 )
107
108 // Login page
109 router.get(
110 '/login',
111 handler(async (req: Request, res: Response) => {
112 res.type('html').send(page(login({})))
113 }),
114 )
115
116 // Login handler
117 router.post(
118 '/login',
119 express.urlencoded({ extended: true }),
120 handler(async (req: Request, res: Response) => {
121 const input = ifString(req.body.input)
122
123 // Validate
124 if (!input) {
125 res.type('html').send(page(login({ error: 'invalid input' })))
126 return
127 }
128
129 // @NOTE input can be a handle, a DID or a service URL (PDS).
130
131 // Initiate the OAuth flow
132 try {
133 const url = await ctx.oauthClient.authorize(input, {
134 scope: 'atproto transition:generic',
135 })
136 res.redirect(url.toString())
137 } catch (err) {
138 ctx.logger.error({ err }, 'oauth authorize failed')
139
140 const error =
141 err instanceof OAuthResolverError
142 ? err.message
143 : "couldn't initiate login"
144
145 res.type('html').send(page(login({ error })))
146 }
147 }),
148 )
149
150 // Signup
151 router.get(
152 '/signup',
153 handler(async (req: Request, res: Response) => {
154 try {
155 const service = env.PDS_URL ?? 'https://bsky.social'
156 const url = await ctx.oauthClient.authorize(service, {
157 scope: 'atproto transition:generic',
158 })
159 res.redirect(url.toString())
160 } catch (err) {
161 ctx.logger.error({ err }, 'oauth authorize failed')
162 res.type('html').send(
163 page(
164 login({
165 error:
166 err instanceof OAuthResolverError
167 ? err.message
168 : "couldn't initiate login",
169 }),
170 ),
171 )
172 }
173 }),
174 )
175
176 // Logout handler
177 router.post(
178 '/logout',
179 handler(async (req: Request, res: Response) => {
180 const session = await getIronSession<Session>(req, res, {
181 cookieName: 'sid',
182 password: env.COOKIE_SECRET,
183 })
184
185 // Revoke credentials on the server
186 if (session.did) {
187 try {
188 const oauthSession = await ctx.oauthClient.restore(session.did)
189 if (oauthSession) await oauthSession.signOut()
190 } catch (err) {
191 ctx.logger.warn({ err }, 'Failed to revoke credentials')
192 }
193 }
194
195 session.destroy()
196
197 return res.redirect('/')
198 }),
199 )
200
201 // Homepage
202 router.get(
203 '/',
204 handler(async (req: Request, res: Response) => {
205 // If the user is signed in, get an agent which communicates with their server
206 const agent = await getSessionAgent(req, res, ctx)
207
208 // Fetch data stored in our SQLite
209 const statuses = await ctx.db
210 .selectFrom('status')
211 .selectAll()
212 .orderBy('indexedAt', 'desc')
213 .limit(10)
214 .execute()
215 const myStatus = agent
216 ? await ctx.db
217 .selectFrom('status')
218 .selectAll()
219 .where('authorDid', '=', agent.assertDid)
220 .orderBy('indexedAt', 'desc')
221 .executeTakeFirst()
222 : undefined
223
224 // Map (unique) user DIDs to their domain-name handles
225 const uniqueDids = [...new Set(statuses.map((s) => s.authorDid))]
226
227 const didHandleMap: Record<string, string | undefined> =
228 Object.fromEntries(
229 await Promise.all(
230 uniqueDids.map((did) =>
231 ctx.identityResolver.resolve(did).then(
232 (r) => [did, r.handle],
233 () => [did, undefined],
234 ),
235 ),
236 ),
237 )
238
239 if (!agent) {
240 // Serve the logged-out view
241 res.type('html').send(page(home({ statuses, didHandleMap })))
242 return
243 }
244
245 // Fetch additional information about the logged-in user
246 const profileResponse = await agent.com.atproto.repo
247 .getRecord({
248 repo: agent.assertDid,
249 collection: 'app.bsky.actor.profile',
250 rkey: 'self',
251 })
252 .catch(() => undefined)
253
254 const profileRecord = profileResponse?.data
255
256 const profile =
257 profileRecord &&
258 Profile.isRecord(profileRecord.value) &&
259 Profile.validateRecord(profileRecord.value).success
260 ? profileRecord.value
261 : {}
262
263 // Serve the logged-in view
264 res.type('html').send(
265 page(
266 home({
267 statuses,
268 didHandleMap,
269 profile,
270 myStatus,
271 }),
272 ),
273 )
274 }),
275 )
276
277 // "Set status" handler
278 router.post(
279 '/status',
280 express.urlencoded({ extended: true }),
281 handler(async (req: Request, res: Response) => {
282 // If the user is signed in, get an agent which communicates with their server
283 const agent = await getSessionAgent(req, res, ctx)
284 if (!agent) {
285 res.redirect(`/login`)
286 return
287 }
288
289 const status = ifString(req.body?.status)
290 if (!status || !STATUS_OPTIONS.includes(status)) {
291 throw new Error('Invalid status')
292 }
293
294 // Construct & validate their status record
295 const rkey = TID.nextStr()
296 const record = {
297 $type: 'xyz.statusphere.status',
298 status,
299 createdAt: new Date().toISOString(),
300 }
301
302 if (!Status.validateRecord(record).success) {
303 res.status(400).type('html').send('<h1>Error: Invalid status</h1>')
304 return
305 }
306
307 // Write the status record to the user's repository
308 let uri
309 try {
310 const res = await agent.com.atproto.repo.putRecord({
311 repo: agent.assertDid,
312 collection: 'xyz.statusphere.status',
313 rkey,
314 record,
315 validate: false,
316 })
317 uri = res.data.uri
318 } catch (err) {
319 ctx.logger.warn({ err }, 'failed to write record')
320 res
321 .status(500)
322 .type('html')
323 .send('<h1>Error: Failed to write record</h1>')
324 return
325 }
326
327 try {
328 // Optimistically update our SQLite
329 // This isn't strictly necessary because the write event will be
330 // handled in #/firehose/ingestor.ts, but it ensures that future reads
331 // will be up-to-date after this method finishes.
332 await ctx.db
333 .insertInto('status')
334 .values({
335 uri,
336 authorDid: agent.assertDid,
337 status: record.status,
338 createdAt: record.createdAt,
339 indexedAt: new Date().toISOString(),
340 })
341 .execute()
342 } catch (err) {
343 ctx.logger.warn(
344 { err },
345 'failed to update computed view; ignoring as it should be caught by the firehose',
346 )
347 }
348
349 res.redirect('/')
350 }),
351 )
352
353 return router
354}